Step 3: Wheels
I used my homebuilt CNC router, so I added some extra details. A jigsaw or bandsaw would work just as well.
Place a flange on the wheels to to mark for drilling the attachment holes. The center of the flange is located 3.5" below the wheel center. The (2) outside wheels require (1) flange pattern and the center wheel needs it on both sides of the wheel.
Optional: Use a round over router bit around both outside edges of each wheel. This will make it look a little better and limit the chipping of the edge as it is used.